PSD2 Strong Customer Authentication Engine: Safeguarding Digital Transactions

What is PSD2 Strong Customer Authentication?

PSD2, or Payment Services Directive 2, introduced a set of regulations aimed at enhancing the security of electronic payments. One key component is the requirement for 'Strong Customer Authentication' (SCA), which mandates that online transactions undergo an additional layer of verification beyond just a password to ensure they are made by the legitimate account holder.

This process typically involves two or more authentication factors, such as something you know (password), something you have (mobile device), and something you are (biometric data). The SCA engine ensures that these factors are used in a way that minimizes friction for legitimate users while deterring fraudulent transactions.

How Does the Engine Work?

The PSD2 Strong Customer Authentication Engine evaluates each transaction based on predefined risk thresholds. It uses real-time data such as the merchant reference fraud rate, average transaction value, and transaction throughput to decide whether a transaction needs additional authentication or can be approved immediately.

For instance, if a transaction falls within the low-value exemption threshold, it may bypass SCA entirely. Conversely, high-risk transactions will trigger an immediate request for additional authentication, ensuring that only legitimate users complete their purchases.

Why Does It Matter?

Implementing PSD2's SCA is crucial for financial institutions and merchants to comply with regulatory requirements. By reducing the risk of fraud, these measures help protect consumers' funds and personal data, fostering trust in digital transactions.

Moreover, effective use of SCA can improve customer experience by minimizing unnecessary authentication steps, thus streamlining the payment process without compromising security.

Real-World Examples

For example, a small transaction from a known and trusted merchant might be exempted from SCA due to its low risk. On the other hand, an online purchase made through a new or unverified merchant could trigger immediate SCA verification.

Another real-world application is in mobile payments where biometric authentication (like fingerprint scanning) can quickly verify the user's identity without requiring them to enter a password.

Frequently asked questions

Try it live

Everything above runs in your browser — open PSD2 Strong Customer Authentication Engine and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.